there are some really sweet body kits for the z31's.
http://www.fxdesigns.com
http://www.kaminari.com/homepage.htm
http://www.zcarparts.com
http://body-kits.com
zcarparts.com i think is the best website for a z31. you can buy everything and the body kit available is the same kit for the japanese z31. it is awesome.
good luck with your decision on which body kit to get